What are the technical features of the ABB high voltage DC circuit breaker and what are the technical problems that have been solved ？（2）

Aug 16, 2017

2.Difficulties and principles of high voltage DC circuit breaker

Difficult point:

The technical of HVDC circuit breakers are extremely highly required. Since the impedance of such a line is low, the time for breaking current is shorter than AC applications. Short circuit faults usually have to be cleared within 5 milliseconds.

It is only a few tens of milliseconds for a pure mechanical high voltage DC circuit breaker to break a circuit, but this is far from enough for a reliable HVDC network.

High voltage DC circuit breaker can be an easy job to do to overcome the semiconductor breaking speed limit.But the semiconductor always located in the current path, it will produce conduction loss, usually accounts for about 30% of the loss of converter station.

Principle:

After switching off,the current steer to the arrester and started to decrease. The fault current in the arrester group forms a reverse voltage, which reduces and eliminates the fault current by consuming the energy stored in the high voltage DC reactor and the fault current path.